Support alternative js runtimes like Bun

[vjpr]

1. Use Bun to run pnpm

I wonder if anyone has tried benchmarking pnpm running with Bun? Can any Bun-specific API's bring perf improvements?

2. Use Bun to run globally installed packages with pnpm

How can Bun be used for running globally installed packages?

I noticed this property in cat "$(pnpm root -g)/../package.json":

~/Library/pnpm/global/5/package.json

	"dependenciesMeta": {
		"node-bun": {
			"node": "/Users/Vaughan/Library/pnpm/nodejs/20.1.0/bin/node"
		}

However everything has hard-coded bin wrappers for Node.js:

$ cat /Users/Vaughan/Library/pnpm/node-bun


#!/bin/sh
basedir=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")

case `uname` in
    *CYGWIN*) basedir=`cygpath -w "$basedir"`;;
esac

if [ -z "$NODE_PATH" ]; then
  export NODE_PATH="/Users/Vaughan/Library/pnpm/global/5/.pnpm/node_modules"
else
  export NODE_PATH="$NODE_PATH:/Users/Vaughan/Library/pnpm/global/5/.pnpm/node_modules"
fi
"/Users/Vaughan/Library/pnpm/nodejs/20.1.0/bin/node"  "$basedir/global/5/node_modules/node-bun/dist/cli.js" "$@"
exit $?

[vjpr]

pnpm seems to read the hashbang from the bin file which means it already works. E.g:

#!/usr/bin/env bun

import './src/cli.ts'

#!/bin/sh
basedir=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")

case `uname` in
    *CYGWIN*) basedir=`cygpath -w "$basedir"`;;
esac

if [ -z "$NODE_PATH" ]; then
  export NODE_PATH="/Users/Vaughan/Library/pnpm/global/5/.pnpm/node_modules"
else
  export NODE_PATH="$NODE_PATH:/Users/Vaughan/Library/pnpm/global/5/.pnpm/node_modules"
fi
if [ -x "$basedir/bun" ]; then
  exec "$basedir/bun"  "$basedir/global/5/node_modules/js/bin/js.ts" "$@"
else
  exec bun  "$basedir/global/5/node_modules/js/bin/js.ts" "$@"
fi

[maschwenk]

Even without using Bun apis, I think using Bun as the runtime could help with some of the perf penalty you get from wrapping pnpm around any given script.